Fragile X Syndrome
Population studies suggest a prevalence of FXS in 1 in 4,000 males and 1 in 8,000 females1
Fragile X syndrome is a genetic disorder that affects intellectual and developmental functioning. It is the most common inherited cause of intellectual disability and autism spectrum disorder. Fragile X syndrome is caused by a repeat expansion in the FMR1 gene, which is responsible for producing a protein necessary for normal brain development. The mutation in the FMR1 gene causes a disruption in the production of the fragile X mental retardation protein (FMRP). Without adequate FMRP, the brain does not function properly, leading to the characteristic features of fragile X syndrome.
Clinical utility
- Individuals & couples experiencing unexplained infertility or a family history of fragile X syndrome.
- Couples undergoing IVF procedures to identifying carrier status which can influence decisions regarding the use of assisted reproductive techniques
- Couples experiencing RPL
- Knowledge of carrier status or a full mutation can aid in understanding the underlying genetic factors involved and guide counseling and family planning decisions for future pregnancies.
When is it recommended?
- You want to find out the cause of fertility problems
- You want to know the risk of having affected offspring
- In the context of fertility, the study of Fragile X syndrome is recommended for women with fertility problems related to elevated FSH concentrations
- Young women with low ovarian reserve or early menopause.
Test specification
| Technique | Variant types | TAT | Sample requirements |
|---|---|---|---|
| TP - PCR | STR | 3 weeks | EDTA Blood, Amniotic Fluid, CVS (In case of Prenatal) and 3-4 ml Maternal Blood in EDTA for MCC |
References:
- Crawford, D. C., Acuna, J. M., & Sherman, S. L. (2001). FMR1 and the fragile X syndrome: human genome epidemiology review. Genetics in Medicine, 3(5), 359–371.
FAQs
How is fragile X syndrome inherited?
Fragile X syndrome is inherited in an X-linked dominant manner. This means that both males and females can be affected, but males are typically more severely affected. Females can be carriers of the condition.
